Parse SOAP request data and modify!

Hi
We are using an sms gateway to send and receive text messages. We have been given a wsdl. I have written a client for it to send sms text messages,which is working as expected.So far so good...
To receive the messages the provider posts the soap request to a configurable server location.The sample request is as follows:

I believe I cannot use request.get parameter() to request the fields.I would like to know if there are any ways to parse the posted request and extract the required fields on the fly and what would be the best possible ways to do it?Also is it possible to filter the sms text message for obscene/offensive content and forward it to another servlet /jsp.Any inputs or pointers in the right direction would be greatly appreciated.